The development of the pronephric duct is a part of the
development of the urinary system, and the
development of the reproductive system. In the outer part of the
intermediate mesoderm, immediately under the ectoderm, in the region from the fifth
cervical segment to the third
thoracic segment, a series of short
evaginations from each segment grows
dorsally and extends
caudally, fusing successively from before backward to form the pronephric duct. This continues to grow caudalward until it opens into the ventral part of the
cloaca; beyond the
pronephros it is termed the
mesonephric duct. Thus, the mesonephric duct remains after the atrophy of the pronephros. ==External links==